This invention relates in general to wheelchairs, and more particularly to braking systems for wheelchairs.
Braking for users of manual wheelchairs can be a challenging task, especially for those with limited mobility/dexterity or while traveling downhill. Descending ramps and sloped sidewalks may present a significant barrier to independent and safe mobility for manual wheelchair users. The most common technique to retard speed is the use of friction on the wheels, either at the tires or push rims.
For persons with poor hand strength and/or sensation, braking action by use of friction on the wheels can be difficult or impossible. A wheelchair user will apply friction to the tires or push-rims with either a bare or gloved hand. Bare hands can be burned from high friction rims during braking, while gloves can reduce sensation for propulsion.
Some users will lean forward to engage the wheel locks against the drive wheel tire to slow down. Wheel locks are intended to provide a stationary engagement once the wheelchair has stopped, and to prevent movement. Many devices are either some form of caliper to grasp the rim of the wheel or a friction assembly contacting the tire surface. Most require the user to remove his/her hands from the push-rim for application of the brakes.
The application of brakes using a wheel lock is undesirable for several reasons. First, it is an incorrect use of a device, akin to slowing a car by using a parking brake. Second, it puts the user's center of gravity far forward of the base of support provided by the wheelchair, potentially causing the user to fall out of the wheelchair. There are several devices currently available that allow the user to apply braking forces through external mechanical measures, but the majority of these devices require the user to remove their hands from the push-rim to apply the brakes.
The inability to control the wheelchair speed places the user at risk of collisions, falls and/or tips. The majority of tips and falls occur in the forward direction, consistent with running into an object at too high of speed.
A need exists for a braking system for manual wheelchair users who do not have full upper extremity function.